Machine for spinning dished articles of sheet metal



Se t. 30 1924.

w. HERDEN MACHQNE FOR SPINNING DISHED AR TICLES 0F SHEET METAL 1924 4 Sheets-Sheet l Filed Feb. 26

Sept. 30 1924. v v w. HERDEN MACHINE FOR SPINNING DISHED ARTICLES OF SHEET METAL 4 Sheets-Shet 2 Filed Feb. 26, 1924 Sept. 30, 1924.

W. HERDEN MACHINE FOR SPINNING DISHED ARTICLES OE SHEET METAL 4 Sheets-Sheet 5 Filed Feb. 26, 1924 II'IIIIIIII I aw- Sept. 30 1924. 115M406 W. HERDEN MACHINE on SPINNING DISHED ARTICLES 0F SHEET METAL Filed Feb. 26', 1924 4 Sheets-Sheet 4 WILHELM HEBIDEN, 0F BERLIN, GERMANY.

MACHINE FOR SPINNING DISHED ARTICLES OF SHEET METAL.

Application filed February 26, 1924.

To all whom 2'25 may concern:

Be it known that I, lVILi-IELM HERDEN, a citizen of the German Republic, and residing at 119 Seestrasse, Berlin N. 65, Germany, have invented certain new and useful Improvements in Machines for Spinning Dished Articles of Sheet Metal, of which the following is a specification.

The subject of this invention is a machine for spinning dished articles of sheet metal, such as lamp shades, which are enamelled after spinning, bowls and the like. Machines of this kind as known hitherto had the disadvantage that the material, viz the metal sheet to be spun, was adversely stressed while being acted on by the spining roller, so that creases were formed in the metal sheet or the sheet was stretched and finally crushed.

The object of the present invention is to overcome these drawbacks of the hithertoknown machines for spinning dished articles and is based on the discovery that for successfully imparting a high degree of camber to an article it is necessary that the spinni-ng roller shall throughout the operation be normal to the tangent of the convex surface of the former, i. e. that the spinning roller during the operation shall swivel about the centre of curvature of the convex surface of the former,'so that the particular shape of the surface of the spinning roller shall retain its correct position with respectto the metal sheet.

A further object of the invention is to cause the pressure of the roller against the blank to increase steadily during the spinning operation in accordance with the increase in the peripheral speed of the roller, 011 the latter being advanced. During the forward feed of the roller the stressing of the blank is to remain constant. Hence the forward feed of the roller must be slower the further the roller moves from the axis of rotation of the former.

It is of importance for the persons attending to the spinning lathes from the point of view of their safety and health, to make the construction of these machines such that the position of the operator while attending to the machine shall not. as hitherto be at one side in line with the former. The rapidly rotating blank, in the centrifugal direction of which the workman must then take his stance, is a constance source of danger for the said workman, which can- Serial No. 695,387.

not be overcome owing to the peculiar nature of the work, even by the provision of protective devices. The bad oil, which frequently contains acid and is flung from the oiled blank, has a bad efi'ect on the health of the worker and ruins his clothing, symptoms of illness, through the skin being attacked by acid, frequently having been also noticed. These disadvantages of the well-known spinning lathcs are also overcome by the invention.

The drawings show two constructional examples of the invention,

Fig. 1 being one such example in front elevation,

Fig. 2 the corresponding plan view and Figs. 3 and 4 similar views of a second constructional form.

The two bearings a of the lathe shown in Figs. 1 and 2, which face each other symmetric-ally, support the main shaft Z), which is driven by means of a counter-shaft, electric motor or the like and rotates the former c. The bed (Z is mounted on the pedestals of the bearings a and acts as a guide for the slide rest 0, which is adapted to be slid on the bed (Z by a leading screw 7 (Fig. 2) and the crank r and thus fixed in a position corresponding to the curvature of the former 0. The slide rest 0 is provided with a vertical, pivotal pin it, about which a guid ing piece 2' is adapted to turn. This guiding piece 2' has a square-shaped extension piece, which slides in the rectangular slot of the arm 70, the arrangement being such that the arm is need not change its position, while the slide rest 6 with its pivotal pin 7?, is slid backwards or forwards. From the square extension piece of the guiding piece 2', there extends a further extension piece of round cross-section, on the surface of which a thread is provided, on to which the disc Z is screwed, by means of which the arm 7: is fixed to the guiding piece i, after the slide rest 6 has been correctly set for any particular piece of work. At. the front of the arm 70 is a universal joint m on which the arm n is pivoted, at the lower end of which the bearing 0 for the spinning roller and the spinning roller 29 are mounted. The roller p is pressed against the blank by means of the weight g, which slides on the crank lever 7', which is pivoted at s and is suspended to the universal joint m by the pivotal part If and the bar a. The latch '0, which is pivoted to the arm a, keeps the cranked lever in position. The weight Q on the cranked lever r is moved to and fro during the spining operation, by means of the forked part w, the controlling rod 421 and the slotted guide y, the forked part w being pivoted on the adjustable pivot a on an extension of the part If.

The blank is spun in the following man-- ner: The arm is swings in the horizontal direction about the pivotal pin it, which is set on the bed of the lathe so as to be vertical above the centre of curvature of the former c. The swinging motion is effected by means of the weight A attached to the rope 'l passing round the disk Z, which is described in greater detail below. During this swinging motion the spinning roller will in the first instance describe the arc of a circle of the radius B (Fig. 1) round the former. During this swinging motion the weight Q will slide outwards on the slide of the cranked lever 1, as is shown in Fig. 2, whereby the pressure of the spinning roller against the blank will be constantly increased. In the case of articles to be spun with an S-shaped contour the universal joint 772. permits the spinning roller to perform a further swinging motion with the radius R about the vertical axis of the universal joint, that is, an outward swing. 1 This outward swin ing movement is effected by the move ment of the weight 9 about the pin 7L being retarded, which may be done auton'iatically or by hand. The movement of the weight g on the slideof the cranked lever 1 is reversed quite automatically, whereby the pressure of the roller 29 is reduced as re.

quired, as, during the outward swinging motion the blank requires only a reduced pressure. The set screws B on the arm 7: prevent the universal joint turning forwards beyond the centre line M-M (Fig. 2).

It is not necessary for the contour of the former to be composed of the actual arcs of circles. The spinning roller is capable of following any curvature of the former as it is suspended so as to be capable of swinging. The radius R may be varied by using bearings for the spinning roller having a different amount of overhang. The pull of the weight A is transmitted by the rope T, which runs over the guiding pulley C to the disc Z and passes around the disc Z to the guide roller D (Fig. 2). The guide roller D isprovidedwith a rope tensioning device,.so that the rope can be adjusted, when the position of the slide rest 6 on the bed (Z has to be changed. The guide rollers C and D are coupled together by the pair of toothed wheels E (Fig. 2), the direction of rotation of one being opposite to that of the other.

The escapement wheel F is rigidly connected to. the guide roller O. WVhile the guide roller C is loosely mounted on the shaft G, the worm wheel H is pinned to the shaft G so as to be rigid therewith. The worm wheel H is coupled up to the guide roller C by means of the pawl J and the ratchet wheel F. The operation of the device is as follows:-

The worm wheel H is continuously rotated in the direction of the arrow by means of the worm K. The speed of rotation of the worm wheel H corresponds to the highest speed of the forward movement, which may be imparted to the spinning roller 10 without stressing the sheet metal excessively. The guide roller 0 during the operation of the weight A rotates with the worm wheel. It will, however, rotate more slowly than the worm wheel the greater the resistance of the sheet metal from which the article is being produced, that is to say, the further the spinning roller p is fed forward. During the first portion of the spinning operation the guide roller C will as a rule rotate at the same speed as the worm wheel because at this moment theresistance of the sheet metal is still small. The guide roller 0, however, can never rotate faster than the WI'IOI'IH wheel because the pawl J prevents t is.

The end of the rope on the guide roller D prevents any overrun of the spinning roller 79 (since the rope rolls off the guide roller 1) positively), which might possibly take place if the spinning roller were by any chance to be impelled forward forcibly either by hand or by chattering of the sheet metal being operated on, if this rope were not there, because theend of the pulling rope in front of the guideroller C would have to break before this could take place.

The sheet metal, which is perforated or provided with a cent-re pop at the centre, is pressed against the former 0 by means of the arm L, which guides the pin N, the pressure which is exerted by the compression spring 1 being transmitted through the shaft Q to the arm L. The workpiece to which the pressure is applied. can be removed from the machine by pulling the handle S.

The machine is not provided with a tail stock, whereby the end of the machine is unobstructed and the space in front thereof is available as the operating position of the machine attendant. All the hand controls for operating the machine during the Working period are arranged conveniently at the end of the machine. By this means the operators stance is removed from the dangerous and disagreeable zone within which the sheet and oil is liable to be thrown out by centrifugal force. Further, the room necessary for the machine is reduced to a minimum. g

In the constructional form shown in Figs. 3 and 4 a universal joint m is cast in one piece, with the hollow cylinders 1 and 2 (Fig. 3), which are arranged at right angles .to one another, the interiors of both cylinders communicating with each other by means of the pipe 3. A plunger 4 of small diameter extends into the hollow cylinder 1., the said plunger being guided by the gland 5 and carrying on its upper end outside the hollow cylinder the weight g. A plunger 6 of larger diameter works in the hollow cylinder 2, being guided therein in a pressure-tight manner by means of the gland 7 and carrying on its free outer end the spinning roller p. Both hollow cylinders and their connecting pipe 3 are filled with water. The pressure of the weight g is transmitted by means of the plunger 4 to the water, which in turn transmits pressure to the plunger 6 and the spinning roller 22, the pressure being thereby increased by an amount equal to the square of the ratio of the diameters of the plungers 4 and 6. The lever 8 enables the plunger 6 to be drawn back, the cranked lever moving into the position shown in broken lines in Fig. 3 and in consequence thereof remaining automatically locked in the inoperative position.

The degree of pressure. exerted by the spinning roller is regulated by means of the adjusting weight 9 (Fig. 4), which, by means of the forked lever 10, acts on the weight g from below, tending to raise it, the fulcrum of the lever 10 being provided by the roller 11, which in turn is pivoted on the stationary arm 12 so as to be capable of rotating in a horizontal direction. By this means a portion of the weight g is taken off; the pressure thereof, as will be clear from an inspection of Fig. 4, is a minimum at the commencement of the spinning operation and rises continuously as the arm 12 rotates forward and the fulcrum of the lever lO is displaced in accordance with the variation of the length of the levers 13 and 14 4). This variation in the pressure can be read off directly from the pressure gauge 15.

In the constructional form shown in Figs. 3 and 4 moreover, means are shown for automatically adjusting the position of the spinning roller, that is to say, the outward swing. thereof. The eccentric rod 16 is pivoted at 17 on a pivot, which is ofiset to the pivot of the arm la, the other end of the said eccentric rod embracing the plunger 4. During the rotation of the arm is the axis of rotation of the universal joint must necessarily be displaced, as will be seen from Fig. 4. The magnitude of this displace ment is capable of being varied by altering the amount of offset and the position of the pivot of the eccentric rod 16, so that any predetermined displacement can be ob tained.

If the spinning roller be turned by means of the disc Z and the weight A, the movement of the universal joint will be afi'ected by the eccentric rod 16 in that the universal joint will swing by its vertical axis about the pivot 17 of the eccentric rod. Ac cording to the amount of offset provided the distance between the vertical axis of rotation of the universal joint m and the centre of the disc Z or of the pivot it will be shortened. Thus, as the distances from this centre to the spinning roller p (111 Fig. 4) and from the spinning roller 72 to the vertical axis of rotation of the universal joint m (I Fig. 4) are invariable and in the position of rest the distance IV is approximately equal to the distance H (distance between 17 and m), then the universal joint 711, will rotate slightly, as shown in Fig. 4. The spinning roller 29 will thus be displaced by an amount corresponding to the curvature of the former.

While in the constructional form shown in Figs. 1 and 2 the pivot of the arm 7r can only be displaced on the bed (Z in the direction of its longitudinal axis, in the constructional form shown in Figs. 3 and 4, a lateral displacement of this pivot is possible, that is to say, in a direction at right angles to the longitudinal axis of the bed (Z, because the slide rest e is provided with guiding means and a lead screw. 1

Additional guide pulleys are also required for guiding the ends of the rope. This particular arrangement is of considerable advantage if articles of parabolic shape or pointed cones are to be spun on the machine, because by this means the most suitable position of the pivot of the arm 70 is situated laterally of the longitudinal axis.

lVhat I claim is 1. A. machine for spinning dished articles of sheet metal comprising in combination, a curved former, a pivoted arm movable in a horizontal plane and having its vertical axis of rotationvertically above and coaxial with the center of curvature of said former, a member pivotally mounted on said arm, a spinning roller suspended from said member, andmeans cooperating with said arm for guiding the spinning roller over the former.

2. A machine for spinning dished articles of sheet metal comprising in combination a curved former, a bed arranged above said former, an adjustable vertical pivot provided on said bed, means for setting said. pivot with its axis vertically above and coaxial with the centre of curvature of said former, an arm rotatably mounted on said pivot, a member pivotally mounted on said arm for movement in a horizontal plane, a spinning roller suspended from said member and means co-operating with said arm for guiding the spinning roller over the former.

3. A machine for spinning dished articles of sheet metal comprising in combination a curved former, a pivoted arm movable in a horizontal plane and having its axis of rotation vertically about the center of curvature of said former, a member pivotally connected to the arm for movement about a vertical axis, a second member pivotally connected to the first member for movement about a horizontal-axis, a spinning roller carried by the second member, and. means cooperating with said arm for guiding the spinning roller cover the former.

i. A machine for spinning dished articles ofsheet metal comprising in combination a curved former, a pivoted arm having its axis of rotation verticallyabove the center of of sheet metal comprising in combination a curved former, a pivoted arm having its axis of rotation vertically above the center 01 curvature of said. former, a spinning roller suspended from said member, means cooperating with said arm for guiding the spinning roller over the former, and a counterweight for feeding the spinning roller over the blank in such manner that the pressure at which the spinning roller is fed forward against the sheet metal of the blank is constant throughout the spinning operation. 6. A machine as claimed in claim 1, having manually operated controls arranged in a line at right angles to the axis of the former, outside of the zone in which sheet metal and oil is liable to be thrown out by cenl trifugal force from the blank.

7 A machine fol-spinning dished articles of sheet metal comprising in combination a curved former, a pivoted arm having its axis of rotation vertically abovethe centre of curvature of the said former, a universal joint provided on said arm, a spinning roller mounted on said universal joint, means co-operating with said arm for guiding the spinning roller over the former, means for pressing said spinning roller against the blank intended tobe spun, a hydraulic press provided on said arm for transmittingthe pressure from said pressing -means to the spinning roller, said hydraulic-press having a pressure plunger actuable by said pressing means, a balance weight for relieving said plunger of part: of the pressure applied thereto by said pressing means and means interposed between said balance weight and said plunger for reducing the action of the balance weight on the plunger as the spinning roller is fed {forward over the blank.

8. A machine for spinning dished articles of sheet metal comprising incombination a curved former, a pivoted arm having its axis of rotation vertically .above the centre of curvature of the said former, a universal joint provided on said arm, a spinning roller mounted on said universal joint, :means co-operating with said arm tor guiding the spinning roller over the former, a'fixed pivot having its axis offset with respect .to the axis of rotation of said arm, said pivot being capable of adjustment for varying the amount of offset and an eccentric rod pivoted on said pivot and connected tosaid universal joint, whereby during the rotation of the arm for moving thespinning roller over the former the distance between the universal j ointand the axisof said pivot is reduced, so that the universal .joint will be flexed about its vertical axis therebysetting the spinning roller correctly with .respectto the former.

9. A machine for spinning dished articles of sheet metal comp-rising in combination a rotatablecurved former, a pivot pin having its axis arranged at one side of the axis of rotation of the former and intersecting the center of curvature of the former, anarm mounted on said pin for movement in a plane parallel to the axis of rotation of the former, a member pivotally connected to said arm for movement in a planeperpendicular to the plane of movement of said arm, a spinning roller carried by saidmemher, and means cooperating with said armfor guiding the spinning roller over the former.

In testimony whereof I have signed my name to this specification. 

